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authorChristoph Hellwig <hch@lst.de>2017-02-08 14:46:48 +0100
committerJens Axboe <axboe@fb.com>2017-02-08 13:43:06 -0700
commit34fe7c05400663e01e23cddd1fea68bb7a2b3d29 (patch)
treec03679f3bf7602925ecd9cbd6849af412b06d959 /block/blk-core.c
parent6cf7677f1a94546e472658290b3b8bdbb16cc045 (diff)
downloadlinux-34fe7c05400663e01e23cddd1fea68bb7a2b3d29.tar.bz2
block: enumify ELEVATOR_*_MERGE
Switch these constants to an enum, and make let the compiler ensure that all callers of blk_try_merge and elv_merge handle all potential values. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/blk-core.c')
-rw-r--r--block/blk-core.c76
1 files changed, 40 insertions, 36 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index 1d263311353a..00e053c704a1 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1511,12 +1511,11 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
{
struct blk_plug *plug;
struct request *rq;
- bool ret = false;
struct list_head *plug_list;
plug = current->plug;
if (!plug)
- goto out;
+ return false;
*request_count = 0;
if (q->mq_ops)
@@ -1525,7 +1524,7 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
plug_list = &plug->list;
list_for_each_entry_reverse(rq, plug_list, queuelist) {
- int el_ret;
+ bool merged = false;
if (rq->q == q) {
(*request_count)++;
@@ -1541,19 +1540,22 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
if (rq->q != q || !blk_rq_merge_ok(rq, bio))
continue;
- el_ret = blk_try_merge(rq, bio);
- if (el_ret == ELEVATOR_BACK_MERGE) {
- ret = bio_attempt_back_merge(q, rq, bio);
- if (ret)
- break;
- } else if (el_ret == ELEVATOR_FRONT_MERGE) {
- ret = bio_attempt_front_merge(q, rq, bio);
- if (ret)
- break;
+ switch (blk_try_merge(rq, bio)) {
+ case ELEVATOR_BACK_MERGE:
+ merged = bio_attempt_back_merge(q, rq, bio);
+ break;
+ case ELEVATOR_FRONT_MERGE:
+ merged = bio_attempt_front_merge(q, rq, bio);
+ break;
+ default:
+ break;
}
+
+ if (merged)
+ return true;
}
-out:
- return ret;
+
+ return false;
}
unsigned int blk_plug_queued_count(struct request_queue *q)
@@ -1595,7 +1597,7 @@ void init_request_from_bio(struct request *req, struct bio *bio)
static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio)
{
struct blk_plug *plug;
- int el_ret, where = ELEVATOR_INSERT_SORT;
+ int where = ELEVATOR_INSERT_SORT;
struct request *req, *free;
unsigned int request_count = 0;
unsigned int wb_acct;
@@ -1633,27 +1635,29 @@ static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio)
spin_lock_irq(q->queue_lock);
- el_ret = elv_merge(q, &req, bio);
- if (el_ret == ELEVATOR_BACK_MERGE) {
- if (bio_attempt_back_merge(q, req, bio)) {
- elv_bio_merged(q, req, bio);
- free = attempt_back_merge(q, req);
- if (!free)
- elv_merged_request(q, req, el_ret);
- else
- __blk_put_request(q, free);
- goto out_unlock;
- }
- } else if (el_ret == ELEVATOR_FRONT_MERGE) {
- if (bio_attempt_front_merge(q, req, bio)) {
- elv_bio_merged(q, req, bio);
- free = attempt_front_merge(q, req);
- if (!free)
- elv_merged_request(q, req, el_ret);
- else
- __blk_put_request(q, free);
- goto out_unlock;
- }
+ switch (elv_merge(q, &req, bio)) {
+ case ELEVATOR_BACK_MERGE:
+ if (!bio_attempt_back_merge(q, req, bio))
+ break;
+ elv_bio_merged(q, req, bio);
+ free = attempt_back_merge(q, req);
+ if (free)
+ __blk_put_request(q, free);
+ else
+ elv_merged_request(q, req, ELEVATOR_BACK_MERGE);
+ goto out_unlock;
+ case ELEVATOR_FRONT_MERGE:
+ if (!bio_attempt_front_merge(q, req, bio))
+ break;
+ elv_bio_merged(q, req, bio);
+ free = attempt_front_merge(q, req);
+ if (free)
+ __blk_put_request(q, free);
+ else
+ elv_merged_request(q, req, ELEVATOR_FRONT_MERGE);
+ goto out_unlock;
+ default:
+ break;
}
get_rq: